Remove patching from Generate commands

[simivar]

As discussed in #354 we can remove "patching" existing files from Generate commands as it is quirky and doesn't provide much value and only complicates the codebase.

[veewee]

Thanks for the pr. Will take a deeper look soon.
This will introduce a bc break. Maybe time to list some things we want to change for v2 @janvernieuwe ?

[simivar]

If I think correctly you mean it's BC break because we've deleted a protected method that could've been extended by someone. If that's the case what do you think about, for now, removing only the body contents so we could get it to 1.x version, marking it as @deprecated, and then removing it altogether in 2.x?

[veewee]

Yes indeed, but on top of that - it is a BC break for the people who might rely on this feature to work this specific way. After the change, the cli tool will work in a different way. This might result in broken code downstream.

[veewee]

@simivar
I've pointed this PR to a new 2.0.0 branch in which we will introduce this change.
We could also accept a PR for v1.0.0 that introduces deprecation warnings. But that logging might get lost in the output of the CLI command - so for me it is also fine to describe it in an upgrading section when releasing v0.2.0

[veewee]

Sorry for the long delay. Wanted to play around with this one before merging :)

Thanks for your work!